Train-control system



Feb. 1o; 1925.

w. W. MACFARLANE TRAIN CONTROL SYSTEM 1914 2 Sheets-Sheet 1 Original .Filed Oct. 19,

Feb, 10,1925. v1,526,073

'I W. W. MACFARLANE TRAIN CONTROL SYSTEM Original Filed Oct. 1.9, 1914 2 SheetS-Sheet 2 v Patented Feb. 10, 1925.

UNIED STATES PATENT OFFICE.

WILLIAM W. MIACFARLANE, OF ELKENS PAK, PENNSYLVANIA, ASSIGNOR TO MAC- FARLANE COMMUNCATIONS COR-PORATON, OF NEVfvYOB-K, N. Y., A. CORPORATION TRAIN-CONTROL SYSTEM.

Continuation of application Serial No. 867,316, filed October 19, 1.914. This application filed March s, 191e, sei-iai No. 22,861.

l-"o a?? 107mm t may con-cern ie it known that l, VViLLIAM 1V MAC- iainLANn. a citizen of the United States, and a resident of Elkins Fark, the count-y of Montgomery and State of Pennsylvania, have invented certain new and useful lmprovements in TrainsControl Systems, of which the following is a speciiication.

This invention relates to railway signaling and more especially to signaling systems in which train-carried controlling devices are automatically controlled by track conditions and is a continuation of applica.- tion Serial No. 867,316, filed Oct. 19, 1911i.

The principal object of the invention is to provide a simpliiied method for utilizing the track circuit to continuously control a moving train without the use of ramp rails or continuous contact rails other than the traliic rails themselves.

This invention consists essentially of a train-carried controlling device held in continuous bridging contact with the' track rails and having a suiticiently low resistance to practically short-circuit the kadjacent wheels and axles and utilize substantially the entire track-circuit current flow from rail to rail. to control the train. By this simple expedient the ramp rails with their connecting control wires, and the continuous contact rails, of prior devices are done away with and at the same time a continuous control of a moving train is provided. @ther features of the invention will be referred to 'as the speciiication proceeds.

The invention will be hereinafter fully set forth in a preferred embodiment, and particularly pointed out in the claims.

In the drawings:

Fig. 1 is a plan view, partly in section, showing the Contact shoes and the low resistance relay.

Fig. Q. is a side elevation, partly in section, of the parts shown in Fig. 1.

Fig. is a view showing a detail of the low rcsistancerelay.

Fig. 4- is an end view in section of the parts shown in Fig. 8.

Fig. 5 is a diagrammatic view of the Vlow resistance relay shown in bridging relation with the rails.

F 6 is a general diagrammatic view of Serial No. 281,816.

a track circuit adapted to be used with the devices of Figs. 1 to 5 inclusive.

Like reference characters designate like parts in the several. views.

In the drawings 1 designates a train-carried translating device which is arranged in continuous bridging engagement With, so as to be continuously responsive to, current flowing in the track rails 2 and 3. In order to insure that suiiicient current will be diverted from the path formed by the wheels and axles to flow from rail to rail through the translating device to cause the operation of train controlling means, the translating device is constructed to 'offer an extremely low resistance to the passage of current therethrough.

rlhe translating device l consists of a helical strip e of copper, or other highly conductive material, having a considerable cross-sectional area as shown in Figures 13 and 14 and is preferably produced by helically cutting a solid bar ofV copper. Attached to the ends of the coil 4 by means of the clamps 5 are the copper cables 6 which lead to and are embedded in the contact shoes 7.

The contact shoes 7 preferably have a grid formation 'as is shown in Figures 1 and 2, and have a steel base, or main portion S, and an upper portion 10 of copper which is cast about the cable 6 and into the slots y9 of the base 8 so vas to make contact with a large area of the track rail surface. By this construction a contact shoe is provided which combines the high conductivity characteristic of copper with the wear resisting qualities of steel. The combined re sistance of the contact shoes 7, the copper cables 6, and the copper coil 4t is so`low as to virtually short-circuit the adjacent Wheels and axles of the vehicle. So marked is this difference in the resistance values between the current path through the coil el and the current path from rail to rail through the wheels and axles of the Vehicle that., in the preferred embodiment of the device, the contact shoes are placed Vjust to the rear of the forward driving wheels of the locomotive. Notivithstanding the fact that there are a plurality of Wheels and axles between the contact shoes and 'the source of current in this situation, the resistance value of the translating device can be made so low that no appreciable shunting effect on the part of suchwheelsfand I axles is apparent, -and sufficient current is available to cont-rol the polarized relayl" in the. path Abetween' the contact shoes.. This resistance value'- can also be readily vadjusted so that an additional axle, such as that of another vehicle, placed across th`e--track rails between the translating ydevice and track *battery* will be sufficient to shunt the translating device.` By placingthe` contact' shoes to the rear of adrivingwheelfa cleared rail surface is insured with the Contact shoes can'engage,

The contact shoes arefp'rovided at the' y ends with the lugs ll to which are connected the eye bolts 12 engaging the-downwardly extending pins 13 and helda place by means of Cotter pins, o r the like, lita. The shoes are normally 'pressed into close enV gagement Withth'e' track rails througlrthe action of the springs lwhich carry the; inverted U-shapednguide members 1:5 at their lower ends. YThe guide members 15 not only bear. downwardly on the Contact shoes but they serve to hold the shoes against movement transversely to the rails.

Toserve as a warning of the breaking of a contact shoe from its fastenings while the' Vehicle'is in motion, a cqnnection such as the wire, or i cable 16, may be provided befk tween thecontact shoes and a valve 17in the. train pipe 18. It will evident that, assuming the vehicle vis movi-ng to the .right in Figure 2, upon a breaking o'runeoupling of the eye bolts 12, forinstance, the inovement of the shoe to the left-relatively to the movement of the train would pull'on the wire 16 toopen the valve 1T and vent.- the train pipe 1,8'to set the brakes and stop the train. Each contact shoe, or each end of each Contact shoe, may be equipped withy a safety device such as the one just described.

The coil 4 is mounted in a casing 19,'v preferably4 of wood, ands profvidedwith a soft iron core 2O separated from the coil Y by a suitable insulating shell 2l.y The' ends of the core are provded with polarized armatures 22 and 23 suitably pivoted 'at 24 andfadapted to be swung into engager, mentwith contact plates 25 and 2jwhenY the armatures are attracted by the adja,- cent poles of the core 20. Stops 247' are provided against which the armatures are biased by gravity to engage when they are in unattracted condition.

It'will beV seen that the coil fl, the core 20 and the armatures 22 and 23 form a polarized relay which is responsive to changesin the characteristic of the cunrent flowing in the track rails andto the presence caution., and' danger.

well. The changes in the characteristic of the track circuit are preferably produced by changing the polarity of a. direct current lont suchi'ch'anges may be produced in various other ways, such as by changing the phase or frequency of an alternating current.

lVhen:currentnflows through the coil il in a certain direction, say from-:thetrack -rail3`t'o'the-track rail 2, the soft iron core 2O is given such a polarity that the armature 231s attracted and moved into engagement with the contact member 26,'while the other armature 22 is not only repelled by the adjacent pole of the core 20 but it is also urged by gravity o utfof engagement with the contact piece2A andinto engagement with the stop 27. lYhencurrent flows through the coil lintheopposite direction, that is from trackrail 2ftotrack. rail 3, the armature 22 is attracted so that it will move into engagement with the contact member 25 and atthe Sametime the armature 23 will break con-tact with the contact member Then .no currentl is flowing through the coil both armatures 22 23 move out of engagement withftheir respective contaets.v

l/Vev thus harte three conditions of the polarized relay l whichare made'to corre* spondto the three traffic conditions, safety, Under safety tratlic conditions the armature 23 is caused to make contact with the contact member 2G while the arinaltureY is moved away from the contact 25. Under caution conditions the armature 22y is attracted. and moved into contactl with theV contact member 25 while the armatdre .2l-Sis moved out of engagement with the contact member 26. Under dangerconditicmsy both armatures will leave their respective contacts.

In order to control the operation of the low resistance relay a track circuit system such as is illustrated in Figure V6 of the drawings may be used. The particular lll() rangement of circuits shown, however, is i intended only for an: example and it is to be understood that other and various arrangements may be employed such as will best fit ythe conditions of different installa tions.

The track rails-2 and 3 are divided into suitableblock sections A, B, C, D anc E which are insulated from each other in the usualmarinera` Each block is provided at the exit end with a source of current 28 normally. connected through the conductor 2,97., contacts 30, conductor 3l, and conductor 32, tothe track rail 3, and through the conductor 33 Aincluding the resistance 3st, and eonductor 3,5, to the track rail 2. The source. of current is designed tok furnish the ordinary low voltage `current to the or absence lof current the track rails asv track rail circuit but preferably differs from the ordinary tracksource ,heretofore used in that it is arranged to tarnish a current of comparatively large vo-lume relatively to that supplied by the usual track batter The` track circuit is normally completed through the conductor 36 leading from the track rail 3 at the entrance end o t the block, he pole-changing relay 37, and conductor 33, connected in turn to track rail 2. A circuit-controlling relay 39 is connected by the branch conductors 40 and 4l,- to the conductors 36 and 3S respectively so that the two relays 37' and 39 are arranged in a parallel relation to eachother. The relay 3T has aphigh resistance value while the relay 39 has a relatively low resistance so that Yfor certain values of the track currentthe circuit-controlling vrelay 39 can be energized without energizing the polechanging relay The circuit-controlling relay 39 in its energized condition actuates the circuit closer 42 to bridge the contacts 30 and close a break in the normal or primary track circuit already described. In the deenergized condition ot' the relayv 39 the circuit closer 42 breaks coiitact with the contacts and moves into bridging engagement with the contacts 43 to close a circuit in a secondary, or substitute track circuit which may be traced as follows: current source 28, conductor 29, contacts 43, conductor 44, resistance 45, track rail 2, conductor 3S, conductor 41, relay 39, conductor 40, conductor 36, track rail 3, conductor 3Q, conductor 46, conductor 33, and resistance 34 back to battery. The inclusion ot the two resistances 34 and 45 in series in this circuit so ali'ects the value of the current that the high resistance relay 37 remains deenergized while the low resistance relay 39 is energized to actuate the circuit closer 42.

The pole-changing relay 37 in its energized condition, brings the armature 47 into engagement with the contacts 4S and 49. This serves to connect the conductors 31-32 and 35--33 respectively which form part of' the normal, or primary, track circuit already reterred to. Y in the deenergized condition ot this relay the armature 47 engages the contacts 50 and 5l. This serves to connect the conductors and 32-46 and, when the relay 39 is energized to bridge the contacts 30, establishes a caution circuit as follows: current source 2S, conductor 29, contacts 30, conductor 3l, conductor 52, armature 47, conductor 35, track rail 2, conductor 33, relays 3T and 39, conductor 36, track rail 3, conductor 32, armature 4'?, conductor 46, conductor 33, resistance 34, and back to battery.

The presence of a train, indicated at 53 in block section B, will sliort-circuit the relays 37 and 39 connected to the rails of block B which will result in breaking the normal track circuit and'establish the secondary cir* cuit in block C as has been already explained. r)This circuit in block section C will energize the magnet 39 to bridge the contacts 30 in the normal track circuit of block section D. However, the deenergization or' the pole changing relay 3T connected to the rails 2 and 3 serves to reverse the polarity ot the -track rails in this section so that while the current has the same value that it has in normal conditions, it will tend to flow from rail 2 to rail 3, instead ot from rail 3 to rail 2, as is the case under wholly normal conditions.

lVhat is claimed, is:

l. system ot train control comprising: traiiic tracks divided into blocks, a track circuit, for each block, normally closed through the rails ot the block, a car, a current path on the car the resistance of which is lower than the resistance ot the wheels and axles ot' the car and thro-ugh which the track current passes when the car occupies a block, a translating device in said low resistance path continuously responsive to variations in the characteristic ot' the current ot the track circuit, and means for varying the characteristic ot the current of the track circuit.

fr sv tem ot train control comprising: trattic tracks divided into blocks, a track circuit, for cach block, normally closed through the rails of the block with current `having a certain characteristic, a car, a current path on the car the resistance ot' which lower than the resistance oi the wheels and axles of the car and through which the track current passes when the car occupies a block, and a translating device in said low resistance path continuously responsive to variations in the characteristic or the continuity of the track current.

A system oit' train control comprising: a trafhc track, a track circuit includingl a relatively low voltage source capacitated to deliver a relatively large volume oft current and. including sutlicient resistance to normally prevent the tlow of a. large volume of current, a train having path oft' sniliciently low resistance to short-circuit a part of the resist-ance normally in the track circuit and to permit a relatively large volume of current to ii-ow, and a translating device under the intiuence ot said low resistance path adapted to utilize a current having a relatively lov voltage but recpiiring` a current having a relatively large volume.

4. A system of traiiic control comprising: a trailic track, a track circuit including` a source or" current adapted to produce a current ot low voltage and relatively large volume. a resistance in said track circuit, a train, and a conductor carried by said train arranged to bridge said rails and short-circuit the resistance in said track circuit.,

whereby a current of large volume will ow through said low resistance "conductor.

5. A system of train cont-rol comprising: traiiic rails divided by insulation into conducting blocks, a low voltage source vof electricity capable of delivering a large volume of eurent connecting said rails, a resistance connecting said rails, a train, a low resistance train controlling path on s-aid train through which the circuit is diverted from said track resistance when the train enters a block, whereby a current or large volume passes through the. low resistance path, and whereby a1 current of low volume normally flows through the track circuit when a train is not in the block.

G. A system ot train control comprising: a traliic track, a train having a. plurality of connected pairs ol trafliic wheels traveling on opposite rails oi? the traliic track 'forming parallel paths from one rail to the opposite rail, a track circuit including the rails of the traffic track, a. low-voltage battery in said. track circuit, a low resistance path on the train extending from one rail to the opposite rail and capacitated to conduct a large volume of current to the practical eX- clusion of the remaining parallel paths by ieason of the low resistance of said path, a. resistance element in said track circuit adapted to be short-circuited by the train, a translating device forming a part of the low-resistance path and adapted to be actuated by a low-voltage current, regardless of the drop in potential between the low resistance path and adjacent parallel paths.

7. A system or' traliic controlcomprising: tratlic rails, a track circuit normally closed through said rails, a source of current for said circuit, a high resistance in said circuit, a train carrying a low resistance conductor arranged to bridge said rails and short-circuit the adjacent wheels and axles and the high resistance in said track circuit whereby a current of large volume flows thro-ugh said low resistance conductor, and a translating device under the influence of said low resistance conductor.

S. A system of train control comprising: traflic rails divided into blocks by insulation, a track circuit normally closed through the rails ot each block, a resistance in each circuit whereby a current or' small volume; norii-ially flows through said circuit, a car, a, current path on the car the resistance ot which is lower than the resistance of the axles of the. car and through which the track current passes trom rail to rail when the vcar enters a block to shunt said resistance and permit a large volume o't current to flow, and a translating device in said low resistance.

9. A system of train control comprising:

'a trfack Acirclit -iln olii'` g source of relatively 1 arge volume, a trainlya translating dev-ice fon-the trai-n 'hav' g Vlow resistance and provided with a nu'b'er of ampere turns su'i'cient Ato create a relatively .powerful magnetic fiel'd with ya A'low volta-gecurre'nt of relatifl `lfyla 'ge "volume, and means for supplying 'curretfitu from' said track circuit I'tosaid translating device'.

1Q. A systenfior' vv-traiiio'co"1`it1iv`l comprising: a train, traic rai-ls,-a track circuit having a source adapted jt'o supply a comparatively large volume off current to! said rails,

a translating -devi'ce Von the 'trainoiferin-'g a. suiii'cient-ly low st'al'nce permit a reltherethrough and provid' fg asuiricien't number of ampere turns to Ycr'e'at'e fa. vrelatively powerful magneticfieltd, and means for -supf plying a. suiiicient volume of current 'fr-oni therethrough and' provid-ing a sufficient number 'oit ampere. to vfcr'ea'te vla-lifelatively powerful magnetic field, said translating fdevice lbeing" placed'V in current path in shunt with 'other current paths available 'to conduct ourrentffroin rail to rail across the train, said source of curi 'nt being adapted to deliver currentto' :said rails having av volume'sirch tha' thefpipporti'onate velu-'ine of cu? entsup? -ied A-tothe shunt path 'on the tra-in iis sutcient to operate the translating dev'ce therein. f

12. A systeinof traaccontrol comprising: a. train, -riratlic rails, a low-'voltage source or' current arranged to supply current to said rails, and a fti'fanslating Jd'ei'zice on the train having j`suilicie=ntly low' resistance to permit a. relatively large Volume of current to flow therethrough and providing a sufficient niunber fof ampere turns to create a relatively powerfulinagnetic 'tie-ld, vsaid translating Ede'vi'ce being placed inf -a current path in shunt with other current paths available to conduct lcurrent from rail to rail across the tralin, said source of current being adapted lto 4deliver curren't'to said rails having 'a voluin'e lsuchfthtat the proportion-ate volume of current supplied to the shunt path on the Vtrain is Vsi'ul'cz ent to Operate the translating device therein.

Signed at Philadelphia inv the z'county off Philadelphia and State of Pennsylvania this 6th day fof March A.. D; 1916.

WILLIAM lV. MACFARLANE. Witnesses Y NORMA-N W. JNo. ENNrs, Jr. 

